Flue-Gas Analysis Safety Apparatus

ABSTRACT

Flue-gas analysis safety apparatus  10  for a gas or oil-fired device  30  having an electrical connection and a flue  54  for combustion gases, comprises a hazardous gas detection element  12  for placement in the flue  54  to monitor flue gas, and a controller  14  for automatically regulating a gas to air ratio in the flue gas based on a signal from the hazardous gas detection element  12 . The controller  14  is able to halt a flow of electricity to the gas or oil-fired device  30  if the gas to air ratio in the flue gas cannot be regulated to fall within a predetermined safe parameter. Preferably, the hazardous gas detection element  12  includes a wireless transmitter, and the controller  14  includes a wireless receiver so that the hazardous gas detection element  12  is wirelessly communicable with the controller  14 . A gas or oil-fired device having the apparatus  10 , and a method are also provided.

The present invention relates to flue-gas analysis safety apparatus, toa gas or oil-fired boiler having an electrical connection andincorporating the said apparatus, and to a method of preventing orlimiting carbon monoxide or other hazardous gas exposure from adefective gas or oil-fired boiler assembly having an electricalconnection by using said apparatus.

Leakage of carbon monoxide or carbon dioxide from a cracked, damaged orincorrectly installed flue is hazardous and can result in death.Standalone carbon monoxide alarms are widely available, but are onlyactivated once substantial leakage into the area of the alarm hasalready occurred. Inefficient or damaged boilers can produce dangerouslevels of carbon monoxide or other hazardous gases which are vented viathe flue over extended periods, and even years, without being noticed.When the flue then becomes damaged or blocked, the flue gases withdangerous levels of carbon monoxide or other gases are vented to theinterior of the building causing a serious hazard.

The present invention seeks to provide a solution to these problemswhereby carbon monoxide or other hazardous gases produced by a boileris/are monitored and controlled before leakage to the interior of thebuilding occurs.

According to a first aspect of the invention, there is provided flue-gasanalysis safety apparatus for a gas or oil-fired device having anelectrical connection and a flue for combustion gases, the apparatuscomprising a hazardous gas detection element for placement in the flueto monitor flue gas, and a controller for automatically regulating a gasto air ratio in the flue gas based on a signal from the hazardous gasdetection element, the controller being able to halt a flow ofelectricity to the gas or oil-fired device if the gas to air ratio inthe flue gas cannot be regulated to fall within a predetermined safeparameter.

Preferable and/or optional features of the first aspect of the inventionare set forth in claims 2 to 14, inclusive.

According to a second aspect of the invention, there is provided a gasor oil-fired device having an electrical connection, the device having aflue for combustion gases in which is provided the hazardous gasdetection element of the flue-gas analysis safety apparatus inaccordance with the first aspect of the invention, the gas to air ratioin the flue gas and the electrical connection of the device beingautomatically controllable by the said controller based on an output ofthe hazardous gas detection element.

According to a third aspect of the invention, there is provided a methodof preventing or limiting hazardous gas exposure from a defective gas oroil-fired device having an electrical connection, by using flue-gasanalysis safety apparatus in accordance with the first aspect of theinvention, the method comprising the steps of: a) providing thehazardous gas detection element in a flue of the gas or oil-fireddevice; and b) automatically regulating a gas to air ratio in the fluegas based on a signal from the hazardous gas detection element so as tofall within a predetermined safe parameter, and halting the electricitysupply to the gas or oil-fired device thereby shutting down the saiddevice if the predetermined safe parameter cannot be attained.

The invention will now be more particularly described, by way of exampleonly, with reference to the accompanying drawings, in which:

FIG. 1 shows a first embodiment of flue-gas analysis safety apparatus,in accordance with the first aspect of the invention;

FIGS. 2 to 4 show the flue-gas analysis safety apparatus when in use;

FIG. 5 shows a front elevational view of a controller of the flue-gasanalysis safety apparatus, again when in use;

FIG. 6 shows part of a second embodiment of flue-gas analysis safetyapparatus; and

FIG. 7 shows part of a third embodiment of flue-gas analysis safetyapparatus.

Referring firstly to FIGS. 1 to 5 of the drawings, there is shown afirst embodiment of flue-gas analysis safety apparatus 10 whichcomprises a, preferably at least carbon monoxide, gas detection element12, a controller 14, and a remote carbon monoxide detection device 16.The detection element 12 in this embodiment comprises an elongateflexible wand 18, a preferably at least carbon monoxide sensor 20provided at a distal end of the wand 18, and a slim housing 22 at aproximal end of the wand 18. A battery compartment and wirelesstransmitter are provided in the slim housing 22. Preferably, batteriesare used to power the sensor 20 and the transmitter. However,additionally or alternatively, the detection element 12 may beconnectable to a mains power supply.

The detection element 12 is liquid-resistant and heat-resistant, due toits intended placement in the boiler's flue.

The controller 14 is separate of and spaced from the detection element12, and comprises a, typically moulded plastics, controller housing 24having a plug socket 26 on one side for receiving an electrical plug 28of the boiler 30, and electrical prongs 32 on another side for removableengagement with a wall-mounted electricity supply socket 34. A wirelessreceiver for receiving a signal from the detection element transmitteris provided within the controller housing 24, along with controlcircuitry for controlling a supply of electricity to the electrical plug28 of the boiler 30. A wireless transmitter is also provided forcommunicating with a controller on the gas or oil-fired device whichincludes at least an electronically adjustable air regulation valve andpreferably also an electronically adjustable gas regulation valve. Thecontrol circuitry of the controller 14 automatically controls a gas toair ratio in the flue gas via the controller and valve or valves of thegas or oil-fired device based on feedback from the detection element sothat a safe ratio falling within a predetermined parameter is sought.

The controller 14 of the apparatus 10 also includes a warning circuitwhich is electrically connected to the control circuit. The warningcircuit includes an output device 36, which in this case is a speaker 38for outputting an audible warning signal and a light emitting element40, such as an LED, on the controller housing 24 for outputting a visualsignal.

In the present case, three said light emitting elements 40 are providedas part of the warning circuit. The first light emitting element 42shows a status of the detection element 12, and will change if, forexample, an electrical supply to the detection element 12 fails. In thiscase, the speaker 38 also emits a first audible warning signal.

The second light emitting element 44 changes if the presence of carbonmonoxide above a predetermined level is detected by the detectionelement 12. Again, the speaker 38 also emits a second audible warningsignal, preferably being different to the first audible warning signal.

The third light emitting element 46 displays a status of the remotecarbon monoxide detection device 16. If an electrical supply to theremote detection device 16 fails or if the remote detection device 16detects carbon monoxide above a predetermined level, then the displaycolour changes. In this case, the speaker 38 also emits a third audiblewarning signal, which is preferably different to those of the first andsecond signals.

The remote carbon monoxide detection device 16 comprises a, typicallymoulded plastics, device housing 48 having a battery compartment, awireless transmitter and receiver, a carbon monoxide sensor circuit, anda warning circuit. The transmitter and receiver allow wirelesscommunication with the controller 14 and, preferably also, the detectionelement 12. The warning circuit preferably includes a speaker 50 foroutputting an audible warning signal to alert an occupant of the roomand/or building. The warning circuit may also include a light emittingelement 52, again, such as an LED, for outputting a visual signalshowing the status of the remote detection device 16. Although theremote detection device 16 is preferably battery operated, it may beadditionally or alternatively connected to a mains electricity powersupply.

In use and with reference to FIGS. 2 to 4, the wireless remote detectionelement 12 is slid into the flue 54 of a gas or oil-fired boiler 30.Typically, the flue 54 includes a horizontal portion 56 which dischargesto the outside 58. The exit is usually covered by a grating or grill 60.By removing the grill 60, the wireless detection element 12 can beeasily slid into the flue 54 so that the sensor 20 is facing away fromthe exit and upstream. The grill 60 is then replaced.

The controller 14 is then plugged into a wall socket 34 adjacent to theboiler 30, and the boiler plug 28 is plugged into the socket 26 of thecontroller housing 24. The controller 14 is preferably mains powered,but may additionally by battery powered.

The remote detection device 16 is attached to a surface which ispreferably adjacent to the boiler 30, either being a wall or ceiling 62.

Once operational, the detection element 12 continuously monitors a levelof carbon monoxide and/or other hazardous gas in the combustion gasdischarged from the boiler 30 and along the flue 54. The remotedetection device 16 also continuously monitors a level of carbonmonoxide in the room in which it is located.

If the detection element 12 senses a level of carbon monoxide whichexceeds a predetermined limit or ratio, it sends a signal to thecontroller 14. The warning circuit changes the second light emittingelement 44 to output a visual alert, and the speaker 38 is activated tooutput an audible alert. The control circuitry simultaneouslyautomatically remotely controls the controller of the boiler 30 toregulate the gas to air ratio of the flue gas to bring it back to withina predetermined safe parameter. After a predetermined period dictated byan onboard timer on the controller 14 and feedback from the detectionelement 12, if this cannot be achieved, then the controller halts a flowof current to the housing socket 26, thereby shutting off or disablingthe boiler 30. Once the level of carbon monoxide reduces to below thepredetermined limit, a signal is outputted from the detection element 12causing the controller 14 to reset. Consequently, the boiler 30 can bereignited following servicing and/or repair.

The signal outputted by the detection element 12 is also receivable bythe remote detection device 16, which in turn outputs a warning signal.The remote detection device 16 is also reset following a drop in thelevel of carbon monoxide detected by the detection element 12.

If the remote detection device 16 itself first senses carbon monoxidewhich exceeds a predetermined limit, then it outputs an audible alertand a signal via its transmitter to the controller 14, causing the airto gas ratio in the flue gas to be automatically regulated to a safelevel and, failing that, disabling the boiler 30 as described above. Inthis case, the warning circuit changes the visual appearance of thethird light emitting element 46 on the controller housing 24.

Referring to FIG. 6, there is shown a second embodiment of flue-gasanalysis safety apparatus 10. Like references refer to parts which aresimilar to those of the first embodiment, and further detaileddescription is omitted.

In this embodiment, the detection element 12 and the remote detectiondevice 16 are identical. However, the controller 14 is not removable. Inthis case, the controller 14 is directly electrically connected to amains electricity supply. The gas or oil-fired boiler 30 may either bedirectly and non-removably electrically connected to the controller 14,or may be plugged in as in the first embodiment.

The other features remain the same those described in the firstembodiment.

Referring to FIG. 7, there is shown a third embodiment of flue-gasanalysis safety apparatus 10. Like references refer to parts which aresimilar to those of the first embodiment, and further detaileddescription is again omitted.

In this embodiment, the detection element 12 and the remote detectiondevice 16 are again as described in the first embodiment. However, thecontroller 14 is on-board and fully integrated as part of the gas oroil-fired boiler 30 itself, simplifying automatic regulation anddisabling and dispensing with the need for a transmitter on thecontroller as in the previous embodiments. In this case, the controllerhousing 24 forms part of the boiler housing 64, and typically thecontrol circuit and the warning circuit are provided as part of theelectronic circuitry of the boiler 30 itself.

The boiler 30 is therefore plugged or connected to an electricity supplyin its normal way, but on detection of carbon monoxide and/or otherhazardous gas in excess of a predetermined limit, the control circuitautomatically regulates to bring about a safe ratio and, failing thisafter a period, halts the flow of electricity to the boiler circuit,thus shutting down the boiler 30.

Although particularly applicable to gas or oil-fired boilers, theflue-gas analysis safety apparatus can potentially be applied to any gasor oil-fired device having a flue, such as a fire.

If a power supply of the detection element 12 or the remote detectiondevice 16 is interrupted or stopped, for example, by batteries runningdown, a signal being outputted by the detection element 12 or the remotedetection device 16 stops and thus the warning circuit of the controller14 outputs an audible alert and changes the visual appearance of thefirst light emitting element 42.

The detection element, remote detection device and/or controller may allinclude a test function including a test button for periodic testing ofthe apparatus.

The detection element may not require the wand 18. However, the wand,preferably being flexibly adjustable, is advantageous in that the sensor20 can be placed closer to the entrance of the flue from the boiler bodywithout the detection element falling into the interior of the boilerbody.

Although the detection element is shown as lying on a bottom surface ofthe flue, it may include a clip or other means by which it can be heldspaced from the bottom surface to prevent contact with condensate.

To enable the controller, detection element and remote detection deviceto communicate with each other, any suitable wireless data protocol ormeans can be utilised, such as Wi-Fi, Bluetooth®, radio or microwave.

Although preferably wireless, the controller, detection element andremote detection device may be hard wired to each other.

One, more or all of the light emitting elements of the warning circuitmay include a pre-warning alert on detection of a hazardous gas or achange in the ratio of gases within the flue. The pre-warning alert maycomprise a further different colour and/or sound. For example, when theflue gases are within a predetermined tolerance or parameter, a greenvisual signal is emitted and there is no sound. The pre-warning signalmay, for example, be an orange visual signal and an intermittent sound.The full alert may be, for example, a red visual alert and a continuoussound.

The remote detection device is preferable, and may be dispensed withdependent on necessity. Alternatively, two or more remote detectiondevices can be utilised. In this case, the remote detection devices arepreferably in communication with each other, the detection element,and/or the controller. The or each remote detection device may be in thesame room as the boiler, or any suitable room, such as a bedroom orliving space.

Although the detection of carbon monoxide is preferable, the detectionelement and the remote detection device(s) may additionally oralternatively detect another gas or other gases, preferably beinghazardous, such as carbon dioxide. Ratios or changes in ratios ofconstituent gases within the flue may instead or additionally bemonitored by the detection element.

The distal end of the wand may include a filter element for the or eachdetectable flue gas. In this case, the filter element may be replaceableand/or interchangeable, typically during a service.

Although the detection element is preferably wireless, it may be inwired connection with the controller.

It is thus possible to provide flue-gas analysis safety apparatus whichimmediately alerts an occupant or user of the gas or oil-fired device tocarbon monoxide or other hazardous gas exceeding a predetermined levelin the flue. It is also possible to provide flue-gas analysis safetyapparatus which automatically regulates an air to gas ratio to try toattain a safe parameter, and then failing this immediately shuts down ordisables the boiler in the presence of carbon monoxide or otherhazardous gas which exceeds a predetermined level for a predeterminedperiod. The controller of the apparatus can be a plug in device, thusenabling quick and simple retrofitting to existing boilers, apermanently fixed device which is remote from the boiler, or integratedas part of the boiler. The sensor is preferably in wirelesscommunication with the controller, and can thus be easily located in theflue.

The apparatus thus reduces the chance of having a gas or oil-fireddevice which is malfunctioning over any extended period, thuspotentially saving the lives of the users. The apparatus can also reduceoperating costs of the gas or oil-fired device by highlighting potentialdefects, and furthermore reduce the environmental impact of amalfunctioning gas or oil-fired device.

The embodiments described above are provided by way of examples only,and various other modifications will be apparent to persons skilled inthe art without departing from the scope of the invention as defined bythe appended claims.

1. Flue-gas analysis safety apparatus for a gas or oil-fired devicehaving an electrical connection and a flue for combustion gases, theapparatus comprising a hazardous gas detection element for placement inthe flue to monitor flue gas, and a controller for automaticallyregulating a gas to air ratio in the flue gas based on a signal from thehazardous gas detection element, the controller being able to halt aflow of electricity to the gas or oil-fired device if the gas to airratio in the flue gas cannot be regulated to fall within a predeterminedsafe parameter.
 2. Flue-gas analysis safety apparatus as claimed inclaim 1, wherein the hazardous gas detection element includes a wirelesstransmitter, and the controller includes a wireless receiver so that thehazardous gas detection element is wirelessly communicable with thecontroller.
 3. Flue-gas analysis safety apparatus as claimed in claim 1,wherein the hazardous gas detection element includes an elongate wandhaving a hazardous gas sensor at a distal end.
 4. Flue-gas analysissafety apparatus as claimed in claim 3, wherein the wand is flexiblyadjustable.
 5. Flue-gas analysis safety apparatus as claimed in claim 1,wherein the controller includes a warning element for outputting awarning signal when regulating a gas to air ratio.
 6. Flue-gas analysissafety apparatus as claimed in claim 1, wherein the controller includesa warning element for outputting a warning signal on disconnection fromthe hazardous gas detection element.
 7. Flue-gas analysis safetyapparatus as claimed in claim 1, further comprising a remote hazardousgas detection device for placement remotely from the gas or oil-fireddevice for outputting a warning signal on detection of hazardous gas. 8.Flue-gas analysis safety apparatus as claimed in claim 7, wherein theremote hazardous gas detection device is communicable with thecontroller to halt a flow of electricity to the gas or oil-fired device.9. Flue-gas analysis safety apparatus as claimed in claim 7, wherein theremote hazardous gas detection device includes a wireless transmitterand receiver for transmitting a signal to the controller to halt the gasor oil-fired device and for receiving a signal from the controllerand/or the hazardous gas detection element to output the warning signal.10. Flue-gas analysis safety apparatus as claimed in claim 1, whereinthe controller includes a warning element for outputting a warningsignal on receiving a signal from the remote hazardous gas detectiondevice.
 11. Flue-gas analysis safety apparatus as claimed in claim 1,wherein the controller includes an independent removable housing whichhas a socket for receiving an electrical plug of a gas or oil-fireddevice and prongs for insertion into an electrical socket.
 12. Flue-gasanalysis safety apparatus as claimed in claim 1, wherein the controllercomprises a non-removable surface-mountable housing which is directlyconnectable to a mains electricity power supply, the housing including asocket for receiving an electrical plug of a gas or oil-fired device.13. Flue-gas analysis safety apparatus as claimed in claim 1, whereinthe controller is provided on-board as part of the gas or oil-fireddevice.
 14. Flue-gas analysis safety apparatus as claimed in claim 1,wherein the hazardous gas detection element can detect at least carbonmonoxide.
 15. (canceled)
 16. A gas or oil-fired device having anelectrical connection, the device having a flue for combustion gases inwhich is provided the hazardous gas detection element of the flue-gasanalysis safety apparatus as claimed in claim 1, the gas to air ratio inthe flue gas and the electrical connection of the device beingautomatically controllable by the said controller based on an output ofthe hazardous gas detection element.
 17. A gas or oil-fired device asclaimed in claim 16, wherein the device is a boiler.
 18. A method ofpreventing or limiting hazardous gas exposure from a defective gas oroil-fired device having an electrical connection, by using flue-gasanalysis safety apparatus as claimed in claim 1, the method comprisingthe steps of: a) providing the hazardous gas detection element in a flueof the gas or oil-fired device; and b) automatically regulating a gas toair ratio in the flue gas based on a signal from the hazardous gasdetection element so as to fall within a predetermined safe parameter,and halting the electricity supply to the gas or oil-fired devicethereby shutting down the said device if the predetermined safeparameter cannot be attained.